Dystonia assessment in children with cerebral palsy and periventricular leukomalacia

Tendon transfer in spastic cerebral palsy upper limb

Cerebral palsy (CP) in upper limb produces functional, aesthetic and hygienic issues, and is not always amenable to surgical procedures. We are reporting a single-center, long follow-up experience with tendon transfer in wrist and forearm CP. The CP cases who had undergone tendon transfer in hand, wrist and forearm in a 14-year period were evaluated for change in motion, function and cosmetic appearance and also assessed by Manual Ability Classification System (MACS), and Dash (Disability of Arm, Shoulder, Hand) scores. Forty-two spastic CP patients with a mean age of 19.81 (10-34 years, SD: 5.36) years with a mean follow-up of 5.5 (2-14) years, entered the study. 24 cases were GMFCS I or II and 18 were III or IV. Supination beyond neutral was seen in 48.5%, and improvement in MACS scores in all the cases. Improved 'grasp' and 'release' and keyboard use was seen in 50%, 71% and 87% respectively. The satisfaction from appearance and improved function of 83-96% correlated positively with GMFSC, MACS and DASH scores. Noticeable improvement in personal hygienic care was seen in only 52% of cases. Tendon transfer in well-selected spastic upper extremity CP cases results in long-time improved function, and limb appearance - correlating with initial GMFCS and MACS scores.

Function and dysfunction of the dystonia network: an exploration of neural circuits that underlie the acquired and isolated dystonias

Dystonia is a highly prevalent movement disorder that can manifest at any time across the lifespan. An increasing number of investigations have tied this disorder to dysfunction of a broad "dystonia network" encompassing the cerebellum, thalamus, basal ganglia, and cortex. However, pinpointing how dysfunction of the various anatomic components of the network produces the wide variety of dystonia presentations across etiologies remains a difficult problem. In this review, a discussion of functional network findings in non-mendelian etiologies of dystonia is undertaken. Initially acquired etiologies of dystonia and how lesion location leads to alterations in network function are explored, first through an examination of cerebral palsy, in which early brain injury may lead to dystonic/dyskinetic forms of the movement disorder. The discussion of acquired etiologies then continues with an evaluation of the literature covering dystonia resulting from focal lesions followed by the isolated focal dystonias, both idiopathic and task dependent. Next, how the dystonia network responds to therapeutic interventions, from the "geste antagoniste" or "sensory trick" to botulinum toxin and deep brain stimulation, is covered with an eye towards finding similarities in network responses with effective treatment. Finally, an examination of how focal network disruptions in mouse models has informed our understanding of the circuits involved in dystonia is provided. Together, this article aims to offer a synthesis of the literature examining dystonia from the perspective of brain networks and it provides grounding for the perspective of dystonia as disorder of network function.

Brain Region Size Differences Associated With Dystonia in People With Cerebral Palsy Born Premature

BACKGROUND

Dystonia in cerebral palsy (CP) is classically associated with deep gray matter injury at term gestation, but the patterns of injury associated with dystonia following premature birth are unclear. We examined whether there were brain regional size differences associated with dystonia in people with CP born premature.

METHODS

In this retrospective cohort study, we identified subjects with CP born premature (<37 weeks gestational age) seen at a tertiary care CP center between February 1, 2017, to February 1, 2021, who had T1-weighted brain magnetic resonance imaging (MRI) done between ages one and five years available in the clinical record. We measured the following on these brain MRI images per the 2013 Kidokoro criteria: interhemispheric distance, biparietal width, lateral ventricle diameter, transcerebellar diameter, deep gray matter area, and corpus callosum thickness. We then compared the sizes of these structures between those with and without dystonia correcting for gestational age at birth and gross motor functional ability (univariate general linear models).

RESULTS

Fifty-five subjects met the inclusion and exclusion criteria. Interhemispheric distance was significantly greater in those with dystonia, suggesting decreased cortical volume (P = 0.005). There was no significant difference in the other measured structures between those with and without dystonia, including deep gray matter area.

CONCLUSIONS

Increased interhemispheric distance, not measures of deep gray matter size, correlate with the presence of dystonia in people with CP born premature.

Identifying Effective Treatments for Dystonia in Patients With Cerebral Palsy: A Precision Therapeutics Approach

Recent focus on improving the recognition of dystonia in cerebral palsy (DCP) has highlighted the need for more effective treatments. Evidence supports improved functional outcomes with early interventions for patients with cerebral palsy, but it is not known which interventions are most effective for DCP. Current pharmacologic recommendations for DCP are based largely on anecdotal evidence, with medications demonstrating minimal to moderate improvements in dystonia and variable efficacy between patients. Patients, families, and clinicians have identified the need for new and improved treatments in DCP, naming this as the top research theme in a recent Neurology® publication. Precision therapeutics focuses on providing early effective interventions that are individualized to every patient and can guide research priorities to improve treatments for DCP. This commentary outlines current obstacles to improving treatment of DCP and addresses how precision therapeutics can address each of these obstacles through 4 key components: (1) identification of predictive biomarkers to select patients likely to develop DCP in the future and for whom early intervention may be appropriate to delay or prevent full manifestation of dystonia, (2) stratification of patients with DCP into subgroups according to shared features (clinical, functional, biochemical, etc) to provide a targeted intervention based on those shared features, (3) administration of an individualized dose of an effective intervention to ensure adequate concentrations of the therapeutic entity at the site of action, and (4) monitoring of objective biomarkers of response to intervention. With implementation of each of these components of precision therapeutics, new and more effective treatments for every person with DCP can be realized.

Bradykinesia assessment in children with cerebral palsy and periventricular leukomalacia

OBJECTIVE

To analyse the motor phenotype with a focus on bradykinesia in children with Cerebral Palsy (CP) in the setting of periventricular leukomalacia (PVL).

METHODOLOGY

Analysis of a cohort of 25 children with CP and PVL. The Gross Motor Function Classification System (GMFCS) and the Manual Ability Classification System (MACS) were used to classify the severity of motor function. Spasticity was rated using the Modified Ashworth Scale (MAS), dystonia was rated using the Burke-Fahn-Marsden Scale (BFMS), and bradykinesia was rated using the Unified Parkinson's disease rating scale (UPDRS). All patients were video-recorded following a standard protocol.

RESULTS

Bradykinesia was observed in 96% of patients. It was noted mainly in the limbs, and it was moderate-to-severe in the legs and mild-to-moderate in the arms. Bradykinesia correlated with functional level, as classified by GMFCS and MACS; also with dystonia, as rated by BFMS but did not correlate with a measure of spasticity (MAS).

CONCLUSIONS

This study confirms the existence of bradykinesia in patients with CP in the setting of PVL. Bradykinesia and dystonia appear to be important interrelated factors influencing the level of gross and fine motor skills in patients with PVL.

Dystonia in individuals with spastic cerebral palsy and isolated periventricular leukomalacia

AIM

To determine the prevalence of dystonia in individuals with periventricular leukomalacia (PVL) and spastic cerebral palsy (CP), but without basal ganglia and thalamic injury (BGTI) on brain magnetic resonance imaging (MRI).

METHOD

This was a retrospective study of individuals with spastic CP and PVL on MRI evaluated between 2005 and 2018 in a CP center. Individuals with non-PVL brain lesions on MRI, including BGTI, were excluded. Dystonia was assessed via blinded review of neurological exam videos by pediatric movement disorders specialists.

RESULTS

Eighty-five participants (45 males, 40 females; mean age at videotaping 12 years [standard deviation 5 years 6 months], range 4-26 years) met inclusion and exclusion criteria. Of these participants, 50 (59%) displayed dystonia in their exam videos. The most common locations of dystonia were the fingers and hip adductors. The prevalence of dystonia was unaffected by the gestational age or severity of PVL, and was affected by Gross Motor Function Classification System level.

INTERPRETATION

Dystonia is common in individuals with spastic CP and PVL, even without BGTI on MRI. Our findings suggest vigilance for dystonia in individuals with spastic CP should remain high, even without MRI evidence of BGTI.

WHAT THIS PAPER ADDS

Individuals with spastic cerebral palsy and isolated periventricular leukomalacia on magnetic resonance imaging commonly display dystonia. Common sites of dystonia are in the fingers and hip adductors.

Ultrasound-Guided OnabotulinumtoxinA Injections to Treat Oromandibular Dystonia in Cerebral Palsy

Cerebral palsy (CP) is a group of non-progressive disorders of motor function in children resulting from an injury to an immature brain. In addition to abnormal limb and trunk movement, individuals with CP can experience involuntary muscle contractions of the lower facial muscle groups, causing oromandibular dystonia (OMD). Contraction of the lateral pterygoids and submandibular muscles depresses the mandible. OMD involving the lateral pterygoids can therefore lead to involuntary jaw opening posture, affecting the ability to feed and speak effectively. We present a case series of five patients with CP and OMD that received novel ultrasound-guided onabotulinumtoxinA to the lateral pterygoid muscles. Our goal was to determine if chemodenervation would improve the mouth-closing ability, thus in turn improving the ability to swallow, chew, manage secretions, and communicate. We describe this unique injection method and report a subjective improvement in eating abilities and communication, in addition to a positive upward trend in most patients’ weights, with no significant adverse side effects.